1. Field of the Invention
The present invention generally relates to a frame sequential scanning type color endoscope apparatus where three primary color light pulses, i.e., red, green and blue light pulses are sequentially projected toward an object under medical inspection so as to obtain a color image of the illuminated object. More specifically, the present invention is directed to a color lighting control of a light source unit employed in the frame sequential scanning type color endoscope apparatus.
2. Description of the Related Art
As is well known, in the above-described color endoscope apparatus, the three primary color light pulses, i.e., red, green and blue light pulses are sequentially projected toward the object under examination such as a stomach so as to acquire three color image signals, and thereafter, three color image signals are combined with each other, thereby obtaining one complete color image of the illuminated object, as a color endoscope image.
The above-identified color endoscope apparatus is described in, for instance, U.S. Pat. No. 4,621,281 issued on Nov. 4, 1986.
In the conventional color endoscope apparatus, there is a drawback that the correctly colored image of the illuminated object under examination cannot be reconstructed in case of rapid changes in the movement of the object illuminated by the three primary color light pulses. In other words, a mismatching may occur in the respective R, G, B-colored images due to the positional shifts when the rapidly changing object such as a stomach is illuminated by the three primary color lights. As a consequence, no correct color synthesization is performed in the resultant color image of the rapidly changing object. That is to say, a color misregistration may occur in the RGB color image of the rapidly changing object.
In addition to the above-described drawback, there is another problem in the conventional color endoscope apparatus. When the time durations of the R, G, B color light pulses are selected to be relatively long and the object under examination illuminated by these light pulses is rapidly moved during the light pulse illumination, blurs may be produced in the resultant color image. As a result, a resolution of the resultant color image may be deteriorated.
The present invention has been made in an attempt to solve the above-described drawbacks of the conventional color endoscope apparatus, and therefore has an object to provide a frame sequential scanning type color endoscope apparatus in which occurrences of the color misregistration in the RGB color images can be sufficiently suppressed, and also the blur phenomenon of the RGB color images caused by the rapidly changing object can be mitigated.